Global motion perception is independent from contrast sensitivity for coherent motion direction discrimination and visual acuity in 4.5-year-old children.
Global motion perception is independent from contrast sensitivity for coherent motion direction discrimination and visual acuity in 4.5-year-old children.
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DOI：
10.1016/j.visres.2015.08.007
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发表时间：
2015-10
期刊：
影响因子：
1.8
通讯作者：
Thompson B
中科院分区：
文献类型：
--
作者：
Chakraborty A;Anstice NS;Jacobs RJ;Paudel N;LaGasse LL;Lester BM;Wouldes TA;Harding JE;Thompson B
全局运动处理依赖于包括背侧视觉流的腹外区V5在内的大脑区域网络。由于这个原因，全球运动知觉的心理物理测量已被用于提供背流功能的行为测量。这种方法假设全局运动相对独立于视觉处理层次结构中较早出现的视觉功能，如对比敏感度和视觉敏锐度。我们通过评估整体运动感知、连贯运动方向辨别的对比敏感度（以下简称对比敏感度）和习惯视敏度之间的关系来验证这一假设，研究对象为一大组4.5岁儿童（n = 117）。由于产前药物暴露或新生儿低血糖的危险因素，这些儿童出生时就有神经发育异常的危险。运动一致性阈值，测量全局运动感知，评估使用随机点运动学图。刺激的对比度固定在100%，一致性变化。对比敏感度的测量采用相同的刺激，固定运动相干性为100%和不同的网点对比度。同时测量立体视敏度。运动相干阈值与对比敏感度或视敏度无关。然而，更低（更好）的运动相干阈值与更精细的立体灵敏度相关（rho=0.38, p=0.004）。对比敏感度与视力也有相关性（rho= - 0.26, p=0.004）。这些结果表明，对高对比度刺激的整体运动感知与对比度敏感性和视敏度无关，可用于评估儿童的运动整合机制。
Global motion processing depends on a network of brain regions that includes extrastriate area V5 in the dorsal visual stream. For this reason, psychophysical measures of global motion perception have been used to provide a behavioural measure of dorsal stream function. This approach assumes that global motion is relatively independent of visual functions that arise earlier in the visual processing hierarchy such as contrast sensitivity and visual acuity. We tested this assumption by assessing the relationships between global motion perception, contrast sensitivity for coherent motion direction discrimination (henceforth referred to as contrast sensitivity) and habitual visual acuity in a large group of 4.5-year-old children (n = 117). The children were born at risk of abnormal neurodevelopment because of prenatal drug exposure or risk factors for neonatal hypoglycaemia. Motion coherence thresholds, a measure of global motion perception, were assessed using random dot kinematograms. The contrast of the stimuli was fixed at 100% and coherence was varied. Contrast sensitivity was measured using the same stimuli by fixing motion coherence at 100% and varying dot contrast. Stereoacuity was also measured. Motion coherence thresholds were not correlated with contrast sensitivity or visual acuity. However, lower (better) motion coherence thresholds were correlated with finer stereoacuity (rho=0.38, p=0.004). Contrast sensitivity and visual acuity were also correlated (rho= −0.26, p=0.004) with each other. These results indicate that global motion perception for high contrast stimuli is independent of contrast sensitivity and visual acuity and can be used to assess motion integration mechanisms in children.